Benefits:
extremely thorough
cost (10 blades to 4.49 Euro)
widespread - replacement blades you get around the world
Disadvantages:
less suitable for beginners
requires a little practice
shaving lasts slightly longer than with modern system shavers
I recommend shaving soap and shaving (from badger hair) to use. The shave lasts so in about 3 minutes longer than with shaving gel and razor system, but it is more thorough, more fun and represents a real, morning ritual.